ABC News Congressional Correspondent Rachel Scott, reporting from inside Warnock's headquarters on Tuesday night, said the energy in the room was like a "block party."

"The music somehow gets louder, you have a choir singing over my shoulder here," Scott told "ABC News Live Prime" anchor Linsey Davis.

"People in this room, I can tell you Linsey, they are feeling very confident," Scott later reported. "Just moments ago they said, 'We are almost across the finish line.' This race is still too close to call. Big picture, yes it is tight, but the campaign is keeping their eyes on some of those areas ... right around Atlanta where the votes are still being counted right now. They know that if they do well there and those Democratic-leaning areas, they're going to be on track to have a good night."

Amid the tight race so far, here's what percentage of the expected vote remains uncounted in several Democratic-leaning metro Atlanta counties:

DeKalb County: 35%
Fulton County: 33%
Cobb County: 15%
Gwinnett County: 10%

FiveThirtyEight's Nate Silver gives an analysis of the potential Warnock victory: So if the trend here holds, Republicans are going to wind up not picking up even a single Democratic-held Senate seat. That’s pretty hard to do. Even in 1998 and 2002 (relatively bad midterms for the opposition party), they did pick up at least one Senate seat while others flipped in the other direction.

Marc Short, former Vice President Mike Pence's chief of staff, said Tuesday night as vote counting continued that while the race remained close, he expected outstanding ballots from Atlanta and suburban counties to favor Warnock.

"I would anticipate that you'll see Sen. Warnock widen his lead, which if that is the case, I think it's an incredible indictment against the Republican Party in Georgia because we'll have lost three Senate races within two years in a state where Joe Biden currently has a negative 18 approval rating," Short told "ABC News Live Prime" anchor Linsey Davis.

"I think it is an unfortunate circumstance for Republicans if it does unfold the way I anticipate it will over the last 24% of the vote," Short added.

Pressed on whether there should be a party "reckoning" over candidate quality -- an issue that plagued the GOP this cycle despite polling showing voters disproving of Democrats over inflation and crime - Short told Davis: "I think that reckoning is already happening, it began with the midterm results a month ago."

Watch more from Short's appearance on ABC News Live below.

At an Election Day canvass launch in the metro Atlanta suburb Norcross, Sen. Warnock told supporters not to get deterred by the light rain and to show up big at the polls.

"We're not leaving anything to chance which is why we're standing out here getting sprinkled and baptized. We're leaving it all on the field. But I got a feeling that the people of Georgia are gonna get this right and we're gonna get this done one more time," Warnock said to cheers.

Still, he told supporters not to "rest on our laurels," arguing there was still a pathway to victory for Walker.

"More of our voters tend to vote during the early period. And more of [Walker's] voters tend to vote on Election Day. So if you haven't voted, by all means vote," Warnock said. "And if you've already voted, your job still isn't done until everybody in your circle [votes]."

Warnock said he wasn't thinking about the Senate majority heading into election night.

"I know folks are doing all the other calculations and that's fine. But this really is about who's going to represent Georgia," he said.

Asked about his reaction to Walker's comments that he will "put my character up against Raphael Warnock any day," Warnock told ABC News, "My opponent says many things. You can't believe any of it."